> WhatsApp and Instagram acquisitions needed approvals from EU before they could continue.
What would it mean for a US based company if they decided to acquire two other US based companies and US regulators approved it, but EU regulators didn't?
What would happen if the company went forward with the acquisition anyway?
Most likely, the company would be fined and ordered to either sell off the company or agree to some other set of penalties. If they refused to pay the fine or perform their penalties, they could be banned from operating in the EU. They'd be unable to advertise in the EU, make deals with EU companies, employ people and set up datacentres in the EU, etc etc.
Companies like Facebook aren't "US based" in any way that means anything except for where their CEO normally works and which stock exchange their shares are traded on - they have operations that are central to their business all over the world, and many of those can be disrupted.
They will have to satisfy regulators from all major regions where they want to operate. Non-compliance results financial, or criminal penalties or not being allowed to operate in EU.
In theory FB could just agree with EU that they will cease all operations in EU and leave in peace, but that would effectively kill FB over long term. Competitors would crush them. Imagine a mobile carrier who can't make calls to EU or email provider who can't sent or receive calls from EU. FB is in the same situation. It's a social network. Value for the users comes from connections.
Every international company negotiates some kind of deal if they want to stay international.
"Every person who shall monopolize, or attempt to monopolize, or combine or conspire with any other person or persons, to monopolize any part of the trade or commerce among the several States, or with foreign nations, shall be deemed guilty of a felony"
at least can be halted by the disapproval of antitrust regulators.
That's the key though, they can continue to try until someone sits up and takes notice. Depending on the regulatory climate at any given time a company will have varying degrees of success with this before they are stopped outright before buying any more competition. Either that or they suddenly start abusing their positions such that people/other companies complain enough for regulators to take notice of them.
